This invention relates to plate-stack heat exchangers and especially to plate-stack heat exchangers with internal manifolding.
Finned-plate heat exchangers are mainly of the channel and rib-type construction. Countercurrent flow can be achieved; however, manifolding a plate stack which must separate the fluids at entry and exit becomes extremely complex. Since the manifolding of the crosscurrent heat exchangers is comparatively simple, this heat exchanger system is more widely used although it is less efficient than the countercurrent system and it induces serious thermal and mechanical stresses.
One crosscurrent system which has attempted to solve the manifolding problem of the countercurrent heat exchanger is taught by Campbell et al, U.S. Pat. No. 3,305,010. Campbell et al teach a heat exchanger having superposed stacked plate and fin elements and complex manifolding means for introducing fluids of different temperatures into opposite ends of the assembly. However, Campbell et al do not teach a plate which serves as both the plate and the fin, nor does Campbell et al teach means for internally manifolding the plate within the plate's plane.
One of the problems in the stacked-plate type of heat exchanger is the blocking of a selected internal entry port in a plate at any stack level to prevent fluid flow from the selected port through the channels of that plate and to pass the fluid coming into the port to the next plate level where the fluid is permitted to flow through the channels.